New bio-pesticides for controlling plant pests

Abstract

The present invention relates to cytolytic bi-component protein complexes consisting of a plurality of molecules of a member of the aegerolysin family and a plurality of molecules of a member of the MACPF superfamily, and particularly to their use for controlling a plant pest, such as for controlling Colorado potato beetle ( Leptinotarsa decemlineata ) or Western corn rootworm ( Diabrotica virgifera virgifera ). More specifically, the invention relates to transgenic plants forming cytolytic bi-component protein complexes by a plurality of molecules of one of the aegerolysins ostreolysin and pleurotolysin A with a plurality of molecules of pleurotolysin B (PlyB) or similar proteins, which have been transformed into said plants to be toxic for the aforementioned agricultural pest insects.

1 . A method for protecting a plant against a plant pest and/or controlling or treating a plant pest, comprising the step of: transforming said plant by introducing one or more nucleic acid construct(s) encoding a bi-component protein complex in a plant genome, consisting of a plurality of molecules selected from the group consisting of ostreolysin and pleurotolysin A and a plurality of molecules of pleurotolysin B (PlyB). 
     
     
         2 . The method according to  claim 1 , wherein the transformed plant is subjected to an assay for verifying that said transformed plant has resistance against said plant pest. 
     
     
         3 . The method according to  claim 2 , wherein said assay comprises growing the transformed plant and the control plant not being transformed, and then contacting both plants with said plant pest to assess the difference in resistance to said plant pest. 
     
     
         4 . The method according to  claim 2 , wherein said assay comprises growing the transformed plants and then contacting half of the plants with said plant pest to assess the difference in resistance to said plant pest. 
     
     
         5 . The method according to  claim 1 , wherein the ostreolysin is a polypeptide comprising an amino acid sequence having at least 95% sequence identity with SEQ ID NO: 1. 
     
     
         6 . The method according to  claim 1 , wherein the pleurotolysin A is a polypeptide comprising an amino acid sequence having at least 95% sequence identity with SEQ ID NO: 2. 
     
     
         7 . The method according to  claim 1 , wherein pleurotolysin B is a polypeptide comprising an amino acid sequence having at least 95% sequence identity with SEQ ID NO: 4. 
     
     
         8 . The method according to  claim 1 , wherein the plant pest is an insect of the family Chrysomelidae. 
     
     
         9 . The method according to  claim 1 , wherein the plant pest is an insect. 
     
     
         10 . The method according to  claim 1 , wherein the plant pest is a larva of the insect or an imago of the insect. 
     
     
         11 . The method according to  claim 9 , wherein the insect is of the genus  Leptinotarsa.    
     
     
         12 . The method according to  claim 9 , wherein the insect is  Leptinotarsa decemlineata  (Colorado potato beetle). 
     
     
         13 . The method according to  claim 9 , wherein the insect is of the genus  Diabrotica.    
     
     
         14 . The method according to  claim 11 , wherein the insect is  Diabrotica virgifera virgifera  (Western corn rootworm). 
     
     
         15 . The method according to  claim 9 , wherein the insect is selected from the group consisting  Leptinotarsa decemlineata  (Colorado potato beetle) and  Diabrotica virgifera virgifera  (Western corn rootworm). 
     
     
         16 . The method according to  claim 1 , wherein the plant is a crop plant. 
     
     
         17 . The method according to  claim 1 , wherein the plant is a potato plant. 
     
     
         18 . The method according to  claim 1 , wherein the plant is a maize plant. 
     
     
         19 . A transgenic plant or progeny thereof which expresses or is capable of expressing a bi-component protein complex as defined in  claim 1 . 
     
     
         20 . The transgenic plant or progeny thereof according to  claim 19 , wherein said plant was transformed by introducing one or more nucleic acid construct(s) encoding a bi-component protein complex in a plant genome, consisting of a plurality of molecules selected from the group consisting of ostreolysin and pleurotolysin A and a plurality of molecules of pleurotolysin B (PlyB), so as to obtain said transgenic plant or progeny thereof.